Fuse



AU8- 4, 1931- J. G. cLEMENs 1,817,291

FUSE

Filed Ju ly 27, 1923 Patented Aug. 4, 1931 i UNITED STATES PATENT OFFICE JOHN G. CLEMENS, OF BUFFALO, NEW YORK, ASSIGNOR TO BUFFALO FUSE CORPORA- TION, OF BUFFALO, NEW YORK, A CORPORATION F NEW YORK FUSE Application led July 27, 1923.

This invention relates to a fuse and more particularly a fuse of the knife blade type in which the terminals are constructed in the forni of knife-blade, or fiat plate terminals adapted to fit corresponding sockets on the switch board.

Fuses of this character, as heretofore constructed, have been found objectionable on account of the liability of the fuse going to pieces or being seriously damaged when the fuse blows, also the liability of the flame passing through the fuse and setting fire to nearby objects, and also the cost of making the fuse andthe inconvenience of refilling the same.

It is the object of this invention to provide a fuse which overcomes the various objections above enumerated and which is strong and durable and capable of being easily and quickly refilled with the new fuse link when required.

In the accompanying drawings:

Figures 1 and 2 are longitudinal sections taken at right angles to each other of a fuse embodying my improvements. Figures 3 and 4 are cross sections of the same taken on the correspondingly numbered lines in Figure 1. Figure 5 is an end elevation of the terminal ferrules of the fuse. Figure 6 is a fragmentary longitudinal section, on an enlarged scale, of the joint between the enclosin casing and one of the ferrules. Figure is a cross section on line 77 of Figure o'. Figures 8, 9, 10, 11, 12 and 18 :45 are detached perspective views of some of the parts of the fuse.

ASimilar characters of reference indicate like parts in the several figures of the draw- 1n s:

gIhe frame of the fuse has the form of a tube which is constructed of fiber or other suitable insulating material and is open at its opposite ends while one part of its side is provided with an inlet opening 16 through which the fuse link 17 is introduced into the frame and the fragments thereof after being blown are removed therefrom. Mounted in opposite ends of this tubular frame are the terminals 18, 19 of plate or knife blade form which are arranged out- Seral No. 654,267.

side of the frame and each of which is provided with an inwardly projecting tang 20 forming inwardly facing shoulders 21 on each of the blades at opposite edges of the same and its tang. The tang of cach terminal projects inwardly into the central part of one end of. the tubular frame` and the two tangs are adapted to be connected within the frame by the fuse link so as to complete the electrical connection through the same. The outer parts of the two fangs pass through diametrical slots 22 formed in metal closure and supporting disks 23, 24, each of which engages its outer side with the shoulders 21 of the companion terminal blade while its inner side engages with the adjacent outer end of the tubular frame. The disk 23 is preferably of the same diameter as the periphery of the tubular frame but the disk 24 is of larger diameter so that its marginal part forms an annular flange or shoulder, as shown in Figures 1 and 2,

for a purpose which will presently appear. Arranged within each end of the tubular frame and engaging with the inner side of the adjacent supporting disk is afscreen 25 which is preferably made up of a plurality of disks of woven wire which are assembled side by side and provided centrally with a slot 26 which receives the tang of the respective terminal blade while the peripheral edges of these screen disks engage with the bore of the tubular frame so as to produce a foraminous baffle across the entire end space within the frame. Adjacent to the inner side of each screen is arranged a retaining cup, the interior of which forms an eXp ansion chamberfor the gases resulting from the burning of the fuse link. The cylindrical body 27 of the cup engages its periphery with the bore of the tubular frame and its free outer edge with the inner side of the adjacent screen while the head 28 thereof at the inner edge of the body is provided with a slot 29 which receives the adjacent tang and forms with the screen a vent or relief chamber within this cup.

By arranging these screen disks at the end of the retaining cup instead of inside thevcup as was heretofore done, the disks passing through the joints between the casing and the caps.. The diameter of the bore of the cover or body of the casing is somewhat larger than the periphery of the tubular frame, so as to form an annular relief or vent passage or space 54 between these members which extends beyond the lateral vent openings 32, leading to the relief chambers in opposite ends of the tubular frame.

When the fuse link blows the flame and hot gases generated together with any particles of metal in molten or solid form; first pass laterally outwardly from the tubular frame through thefopening 16 therein and then lengthwise toward opposite ends of the space 54 between the tubular frame and the casing. Upon striking the opposite ends of this space the flame and hot gases rebound and then pass transversely inwardly through the vent openings 32, into the relief or expansion chambers of the cups, thence longitudinally outwardly through the screen whereby the flame is extinguished, and thereafter only the gases underpressure pass lengthwise through the openings 31 to the outer atmosphere. The particles of metal, however, owing to their inertia, do not follow the'gases through the vent openings 32 but strike the ends of the space 54 and remain there until the frame is taken out of the casing, whereupon these metal particles will readily drop out of the fuse casing. By means of this construction the metal cannot reach the screens 25, so that the fuse can be used repeatedly without having the screens become clogged. The gases therefore follow a tortuous path from the time they are generated until they leave the fuse whereby the pressure within the fuse is gradually relieved or deadened and the fuse is prevented from being damaged or impaired when the fuse link blows. In fuses of the construction described, the products of combustion are carried out through the opening 1G in the tubular frame and then into the longitudinal passage, instead of passing lengthwise of the fuse link, as in constructions heretofore used, and this action has a tendency to increase the resistance of the arc formed by the blowing of the fuse link and thus greatly decrease the effectiveness of the arc. These products of combustion seem to conduct current to a certain extent and consequently by leading the products of combustion away from the fuse link and out of the tubular frame, the force of the arc is greatly diminished.

When it is desired to refill, repair or inspect the fuse access to the interior of the same may be had for this purpose by turning the casing backwardly so as to unscrew the same from the respective ferrule which is fixed on the head after which the casing may be moved lengthwise ofthe frame or uncovering the fuse inlet of the frame and the means for fastening the same to the tangs of the terminals.

As a whole this fuse is very simple in construction and efficient in operation. FurthermoreV the same meets the test of the severest requirements and is not liable to get out of order by repeated use. Moreover the same is capable of being manufactured economically on account of the absence of any expensive or delicate operations in its production.

I claim as my invention:

1. A fuse comprising a terminal blade having an inwardly projecting tang and an inwardly facing shoulder between said' blade andtang, a disk arranged on said tang and engagingsaid shoulder and provided with a vent opening, a tubular frame surrounding said tang and engaging said disk, a plurality of layers of screening materia-l arranged within said frame and engaging said disk so as to cover the vent opening therein, and a retaining cup having an imperforate end wall and openings in its side and arranged insaid frame and engaging its open end with said screening material to compress said layers of screening material and to form a chamber into which gases enter laterally before passing through said screening material.

2. A fuse comprising a terminal blade having an inwardly projecting tang and an inwardly facing shoulder between said blade and tang, a disk arranged on said tang and engaging said shoulder and provided with a vent opening, a tubular frame surrounding said tang and engaging said disk, a screen arranged within said frame and engaging said disk so as to cover the vent opening therein, a retaining cup mounted on said tang within said frame and engaging its open end with said screen to form a chamber into which the gases enter before passing through said screen, an enclosing casing surrounding the frame but separated therefrom by an intervening passage, said frame and cup having an opening leading laterally from the interior of the cup to said intervening passage, and a pin passing through the frame, cup and tang.

3. A fuse having a casing adapted to contain a fuse link and having a passage therein into which the products of combustion resulting from the fusing of said link are adapted to pass, a second passage connected with said first passage and extending substantially transversely thereof, a chamber into which said transverse passage leads, and in which the gases discharged from said passage may expand, an outlet from said chamber, and metallic screening material arranged across said outlet.

4. A fuse including ank enclosing casing, a tubular frame arranged in said casing lll and adapted to support a fuse link and forming with said casing a longitudinal passage for products of combustion termed by the fusing of said link and having a lateral opening' communicating with said passage, the ends of said frame being closed, a chamber supported by said frame and connected with said longitudinal passage by a transversely extending passage, and ventopenings ont oi alinement with said transversely extending passages and through which products of combustion pass from said chamber.

5. A fuse including an enclosing casing, a tubular frame arranged in said casing and adapted to support a` fuse link and :forming with said casing a longitudinal passage for products oic combustion formed by the fusing of said link and having a lateral opening communicating with said passage, the ends of said frame being closed, a chamber supported by said frame and connected with said longitudinal passage by a transversely extending passage, vent openings in said chamber, and screening material arranged beyond said chamber and through which gases pass from said chamber to said vent openings.

6. A fuse including an outer shell, a terminal having an inwardly projecting tang,

forming an inwardly facing shoulder between the ends of the terminal, a transversely extending part secured with its outer side against said shoulder, a ferrule having means for releasably securing the same to an end of said shell and having an inwardly projecting flange adapted to exert pressure against said transversely extending part when said terminal is secured on said shell, and lateral projections on said terminal to engage said flange to permanently hold said tei-rule on said terminal.

i'. A fuse including an outer shell, a terminal having an inwardly projecting tang to which ay fuse link may be connected, a transversely extending plate secured to said 'terminal and forming a closure for an end of said shell, a 'errule having means for releasably securing the same on sait shell and having an inwardly projecting flange on the outer portions thereof adapted to exert pressure against said transversely extending plate when the terminal is secured en the shell, and lateral projections on said terminal to engage said flange to permanently held said ferrule on said terminal.

S. A fuse including an outer shell, av trame removably arranged within said shell and spaced therefrom to form a longitudinal passage between said shell and frame, a 1sible member mourned in said frame, a chamber arranged in an end of said trame and vented to the exterior ot' said fuse, and lateral passages connecting said chamber and an end of said longitudinal passage and constitutmg the sole means for conducting products of combustion from said longitudinal passage to said chamber, the removal of said frame from said shell rendering said end of said longitudinal passage accessible to remeve solid products combustion therefrom.

9. A fuse including an outer shell, a ,trame arranged within lell and forming with said shell a paiea extending len' 'he inse, chambersl in the oppor, te ends of said frame and vented to the exterior of said fuse, lateral passages connecting said chambers and said lengthwise passage in the ends of said passage, and a fusible member arranged within said frame and constituting the sole means ior conducting products oi comi? ion from said lo*- U'tndlnal pasto said chambers, said trame being removable in a unit 'freni said shell to render the ends off said longitudinal passage accessible for removal ot solid products of combustion therefrom.

l0. A fuse including an outer shell, a frame arranged within said shell and forming with said shell a passage extending lengthwise or" .said shell, chambers in the opposite ends of said frame and vented to 'the exterior ef' said fuse, lateral passages connecting said chambers and said lengthwise pas: je near the ends et said passage, terminals extending beyond the ends oi' said frame and secured to said frame. a i'usible member arranged within said lrame and connected with said terminals, the. terminal at one end of said frame being arranged to pass through one end of said shell when said shell is placed into operative position about said trame, and a :terrule on the other end of said frame provided with releasable means for securing said frame to said terrule.

ll. A fuse including an outer shell, a frame arranged within said shell and 'ferming with said shell apassage extending lengthwise oi" said shell, chambers in the opposite ends oi said frame and vented to the exterior oiz said fuse, lateral passages connecting said chambers and said lengthwise passage near the ends ot said pl s. ige, terminals extending beyond the ends oi' said frame and secured to said trame, a fusible member arranged within s Yd trame and connected with said terminals, the terminal at one em. of said frame being arranged to pass through one end of said shell when said shell is placed into oper tive position about said frame, a ierrule arranged at the other end of said fuse and perma1 tly ser-.ered in place between said end oi' said Jrame and a projectien oi the other terminal, and interengaglng means on said ferrule and said frame tor securing said errule to said frame.

12. A fuse including an outer shell, a frame arranged within said shell, a terminal having an inwardly extending part secured to said frame, a ferrule adapted to be releasably secured to said shell and having a recess through which said terminal extends,

I and a projection on said terminal extendingv beyond the recess in said'ferrule to prevent removal of said ferrule from said terminal.

13. A fuse including an outer shell, a frame arranged within said shelland movable lengthwise into and out of said shell, terminals secured to the ends of said frame, one of said terminals being arranged to move through said shell into its operative position, a fuse link arranged on said shell and connected with said terminals, a errule permanently mounted on the other terminal, and means on said ferrule and an end of said shell for releasably securing said ferrule to said shell.

14. A fuse including an outer shell, a frame arranged within said shell and movable lengthwise into and out of said shell, terminals secured to the ends of said frame, one of said terminals being arranged to move through said shell into its operative position, a fuse link arranged on said shell and connected with said terminals, a errule hav- `ing an opening therein through which the other terminal extends, a projection on said other terminal for preventing removal of said errule therefrom, and means for releasably connecting said ferrule with an end of said shell.

In testimony whereof I affix my signature.

JOHN G. CLEMENS. 

